Ullhass was an infantrymale of the Race's Conquest Fleet. He was one of several infantrymales in his unit to be captured by American soldiers early in the Race's invasion of the United States. He was kept prisoner with fellow infantrymale, Ristin, under the supervision of his original captor, Sam Yeager. The two Lizards, worked closely with the American authorities, and befriended Yeager over time. The long term imprisonment was not all terrible, as Ullhass was treated well. Ullhass began to see that the human race was not as inferior as he had thought before his capture. Surprisingly, was willing to help his captors in the war, thus betraying his species. After the war ended, he remained in the United States and lived in Southern California with Ristin. He occasionally appeared as an extra in Hollywood films about the invasion.